A lot of people type “1 unit electricity cost in Tamil Nadu” into Google expecting one clean number. I get why, we all want a simple answer. But TNEB doesn’t work that way, and honestly it hasn’t for years. Your rate depends on whether it’s a home, a shop, or a factory, and it also depends on how many units you’ve already used in that billing cycle. Add to that the fact that Tamil Nadu’s electricity setup has actually changed quite a bit since the new government came in this year, and you can see why people are confused. So let’s just go through it properly, category by category, with the actual numbers.
What Changed After the New Government Came In
Earlier this year, after the election, C. Joseph Vijay took over as Chief Minister of Tamil Nadu. One of the first things he did on day one, along with signing orders for a women’s safety task force and an anti-drug task force, was sign off on 200 units of free electricity for domestic consumers. Before this, only the first 100 units were free, no matter how much you used overall. Now, if your total bimonthly usage is 500 units or less, the first 200 units don’t cost you anything.
This wasn’t a small tweak either. Out of Tamil Nadu’s 2.46 crore domestic consumers, close to 2.23 crore of them, which is roughly 90%, use under 500 units every two months. So this order affects almost everyone with a home connection. The state government is footing the bill for this too, an estimated ₹1,730 crore a year in extra subsidy, because TANGEDCO itself is under a heavy debt load and couldn’t have absorbed this on its own.
There’s also been some noise around power cuts since the new government took charge, with the opposition raising it repeatedly. Electricity minister C.T.R. Nirmal Kumar addressed this recently and said tariffs will stay unchanged for the rest of the year, and that a white paper on the actual financial condition of the power sector would be released to clear the air. So if you’re wondering why your bill looks different this year compared to last, this is the background.
So What’s the Current 1 Unit Price Right Now?
For a home connection, your first 200 units cost nothing, assuming your total for the cycle stays at or below 500. After that, the current price starts at ₹4.95 per unit and climbs depending on how much more you use. For a shop or small business, the EB unit rate is ₹6.65 up to 100 units, and then it jumps to a flat ₹10.45 per unit for everything, not just the units above 100. Industries pay somewhere between ₹4.95 and ₹9.40 per unit depending on their category, mostly flat, no free units involved. This applies the same whether you’re checking the current price in Chennai, Coimbatore, or any other part of Tamil Nadu, the state-wide rate doesn’t change by city.
Here’s the domestic slab breakdown in full:
| Bimonthly Consumption Slab | Rate Per Unit |
|---|---|
| 0 to 200 units | Free, if total usage for the cycle is 500 units or less |
| 201 to 400 units | ₹4.95 |
| 401 to 500 units | ₹6.65 |
| 501 to 600 units | ₹8.80 |
| 601 to 800 units | ₹9.95 |
| 801 to 1000 units | ₹11.05 |
| Above 1000 units | ₹12.15 |
Here’s the thing that trips people up. If you go even 1 unit above 500, you don’t just move into a slightly higher slab. Your free units also drop from 200 down to 100. So someone using 501 units ends up paying noticeably more than someone using 499, not because of one extra unit, but because they lost 100 units of subsidy in the process. I’ve seen people genuinely confused about why their bill “suddenly doubled” for what felt like barely any extra usage, and this is almost always the reason.
Commercial Connections Work Very Differently
If you run a shop or any small business, don’t assume your electricity bill follows the same logic as a home. Commercial connections, which fall under the LT-V category, don’t get any free units at all. And the slab structure is much simpler, but in a way that can catch you off guard.
| Bimonthly Consumption | Rate Per Unit |
|---|---|
| 100 units or less | ₹6.65 |
| Above 100 units | ₹10.45 (applies to all units, not just the extra ones) |
This flat-rate-on-everything rule is honestly one of the most misunderstood parts of TNEB billing for small business owners. Cross 100 units, even by a single unit, and the higher rate applies retroactively to your entire consumption for that cycle, not just the portion above 100. A shop that used 105 units isn’t paying extra only on those 5 units, they’re paying the higher rate on all 105. On top of your energy charges and fixed demand charges, there’s also a 5% electricity tax added at the end.
1 Unit Electricity Cost in Tamil Nadu for Industries
Industries don’t have a single blanket rate either, and depending on the size and type of operation, you could fall into different categories with fairly different pricing.
| Industry Category | Rate Per Unit |
|---|---|
| Industries & IT Services (LT-IIIB) | ₹8.25 |
| Cottage & Micro Industries (up to 500 units) | ₹4.95 |
| Cottage & Micro Industries (above 500 units) | ₹7.15 |
| HT-I Industries (High Tension) | ₹7.50 |
Bigger factories that draw a lot of power usually move to HT (High Tension) connections, which come with demand charges calculated per kVA rather than per kW, a different structure altogether. Smaller cottage and micro industries got a bit of relief this year too, they were kept exempt from the general tariff hike that hit other commercial and industrial categories, at least for now.
Does the Rate Change if You’re in Chennai vs Coimbatore vs Anywhere Else?
Short answer: No
TANGEDCO applies the exact same tariff structure across the entire state. A domestic connection in Chennai and a domestic connection in a small town near Madurai pay the same per-unit rate, provided they’re in the same consumption slab. What actually varies city to city is stuff like how often power cuts happen, or how quickly a fault gets fixed, not the price you’re charged per unit.
Why Does Tamil Nadu Even Use This Slab System?
The idea behind telescopic billing, where the rate goes up as you use more, is that it’s supposed to keep basic electricity affordable for lower income households while asking heavier users to pay more. For domestic connections, this genuinely works in your favour if you can keep usage low, since a big chunk of it is either free or cheap. For commercial and industrial categories though, it’s less about a gradual climb and more about hard cutoffs, cross a limit and your entire bill recalculates at the higher rate.
Working Out Your Actual Bill
Knowing the per-unit rate is a start, but actually calculating your bill by hand means accounting for free units, slab jumps, and tax, and it’s easy to get it wrong.
Skip the manual math. Enter your category and units used, and get your exact slab-wise bill instantly.
Frequently Asked Questions
For home connections, it ranges from ₹4.95 to ₹12.15 per unit depending on total usage, with the first 200 units free if your bimonthly consumption stays at 500 units or less. Shops and businesses pay ₹6.65 or a flat ₹10.45 per unit depending on whether they cross 100 units.
After the free 200 units, the rate starts at ₹4.95 per unit for the 201 to 400 range and goes up to ₹12.15 per unit if your total consumption crosses 1000 units in a cycle.
No. TANGEDCO’s tariff is the same across Tamil Nadu regardless of city or district. Your rate depends only on your connection category and consumption slab.
Shops and small businesses under LT-V pay ₹6.65 per unit if usage stays at 100 units or below. Cross that, and a flat ₹10.45 per unit applies to your entire consumption, not just the extra units.
This was one of the first orders signed by CM C. Joseph Vijay after taking office, doubling the earlier 100-unit free slab. It benefits around 90% of the state’s domestic consumers who use under 500 units bimonthly.
As per the electricity minister’s recent statement, tariffs are expected to remain unchanged for the rest of the year, though the government has also promised a white paper explaining the sector’s financial situation in more detail.
The EB unit rate depends on your connection type. For a house, it’s free up to 200 units and then ₹4.95 onwards. For a shop, it’s ₹6.65 or a flat ₹10.45 depending on whether you cross 100 units. TNEB charges per unit are the same across all cities in the state.
It’s the same as anywhere else in Tamil Nadu. Chennai doesn’t have a separate current price, TANGEDCO’s tariff applies uniformly across the entire state based on your consumer category and consumption slab, not your city.
Once a home crosses 500 units in a cycle, the house EB unit rate jumps in stages, ₹8.80 for 501 to 600 units, ₹9.95 for 601 to 800, ₹11.05 for 801 to 1000, and ₹12.15 beyond that, along with the free unit subsidy dropping from 200 to 100.
Last Updated: July 2026, reflecting the current TNERC tariff order and the 200 units free domestic subsidy effective from May 10, 2026.
Disclaimer: The rates mentioned here are for reference. Please check TANGEDCO’s official portal or your physical EB bill for exact, official confirmation.